D.C. Mayor Marion Barry said yesterday that if the victims of the Atlanta child killings "had been Jewish [instead of black], the federal government would have moved faster" to send money to help solve the crimes.

"If they had been anything except black they would moved faster," Barry said in response to a reporter's question, repeating a statement he first made at a memorial service earlier this month for the 20 slain children.

The racial element of the unsolved murders has become prominent in recent weeks, with more than a few black officials, reflecting a general feeling of frustration in the black community, saying that the federal government was slow in responding to requests for federal funds from Atlanta Mayor Maynard Jackson.

President Reagan last week sent $1.5 million to aid the Atlanta investigation, in addition to nearly $1 million sent earlier.

Far from putting an end to the controversy his first statement evoked, Barry's latest remarks, made at his monthly press conference, only seemed to keep the sensitive issue alive.

Hyman Bookbinder, Washington representative of the American Jewish Committee, said that for Barry "to talk about the Jews and imply that we are all safe and protected is outrage. We are going through a period of serious escalation in vandalism aginst Jewish places of worship in this country. I regret that he's being this careless in his articulation.

"It's especially painful for me to hear things like that knowing how silent the world was when 6 million Jews were killed," Bookbinder said.

Alan F. Grip, the mayor's press secretary, moved swiftly to issue a clarification of Barry's remarks and to put to rest an issue he said was being fueled by the press. "He [Barry] is not trying to say that whites don't care," Grip said. "He is saying that in his guts, his perception is that had they been white children, the federal government might have been inclined to provide the help faster than they did.

"He did not mean to single out Jews," Grip said. "He meant if they had been anybody -- and he went on to say if they had been anybody."

Barry's original statement on the Atlanta case came at the Shiloh Baptist Church during the memorial service, where he said, "A certain mood exists in the country, encouraged by the leadership, that it is all right to do anything to black people. Now I maintain that if those 21 white people, we would have no problem (getting the federal government involved." There were 21 missing or slain children at the time, now 22.

Yesterday, when asked by a reporter if he still agreed with his remarks, Barry essentially repeatd the same statement and said, "I stand by that. Now all of a sudden we have $1.5 million," Barry said. "I'm happy, Maynard's happy, everybody's happy. So we're in good shape now."

In addition to sending the money to Atlanta, President Reagan dispatched Vice President George Bush to the scene to check on the probe. At the time he approved the funds, Reagan said, "we moved as quickly as we could. This administration is totally color blind."

Barry, in response to the president's remark, said yesterday that it was "a good statement to make, but it's not a reality statement. Anybody who says they're color blind is not telling the truth about things." Asked if he were referring to Reagan himself, Barry said, "I like President Reagan in terms of his sensitivity to this issue at this point."

On another matter, Barry said that the city will begin selling excess methane gas from the city's sewage treatment plant at Blue Plains to the Naval Research Laboratory. Under an agreement reached last fall, Barry said the city would reap about $100,000 a year in revenue by selling about one-half of the 1 million cubic feet of methane gas produced daily during the routine treatment process at Blue Plains.

Barry said that the Department of Environmental Services, which already is saving fuel costs by using some of the methane gas to heat buildings around Blue Plains, is looking for ways to harness that energy to heat other city buildings to save money.